Electronic HSI

STUDENT GUIDE T-39N/G NATOPS

b. Double needle options - V2 (NAV2), A2, Al, T1, OFF.

3. HDG knob - turn to move bug or, press to put bug on the nose.

4. CRS knob - turn to move CDI bar or press to center bar to direct course inbound to

station SELECTED (see CRS button)

5. CRS button selects VOR 1/2, ILS 1/2, or TACAN for CDI (displays on bottom right) and

display DME or TCN(TACAN DME) in the top left corner of the EHSI.

6. INT knob on panel adjusts lighting intensity.

7. HSI mode

a. CDI with course in upper right, source on lower right (TCN VOR, etc).

b. HDG bug in magenta.

c. Red fail flags for NAV, HDG, or GS.

d. Vertical deviation indicator for ILS glidescope.

e. DME in upper left and/or lower left.

f. White course deviation dots (5 each dot VOR or TCN, 1.25 for ILS).

g. HSI button depressed three times gives TTG, SPD, DME. (SELECT DME ONLY)

8. ARC mode

a. Larger scale of HSI, + 40 of hdg.

b. Nice to use on TACAN or ILS final.

9. MAP mode - Bird's eye view of a/c and selected navaid.

M. Radar - align inertial nav unit (INU) on deck with Lat/Long.

AVIONICS SYSTEMS 8-5